Answer:
D. oooooooooooooookkkkkkkkkkkk
Answer:D
Explanation: The pulmonary air sacs of birds only permit a unidirectional flow of air through the lungs. Unidirectional flow means that air is inhale and exhale through one trachea alternatively. This means the bird lungs only receive largely fresh air which has a high oxygen content during inhalation and do not receive fresh during exhalation. While air flow bidirectional in mammals.
Answer:
Baldness
Explanation: hair loss, or absence of hair. Baldness is usually most noticeable on the scalp, but can happen anywhere on the body where hair grows.
The mutagens that result in cancer damage DNA by (b) weakening the DNA strand or interfering with base pairing. This mutagens are called carcinogens, if they cause a damage to <span>a gene that makes a </span>DNA<span> repair protein, it means that a cell will have less ability to repair itself, and ,as a result, this will lead to formation of cancer.</span>
it is b because you see take a ruler and measure it
